The invention relates to a vehicle roof, in particular a motor vehicle roof.
A vehicle molded roof is known from the prior art, which is of sandwich construction and has an inner shell moulded from foamed plastic that is designed as the roof interior.
This type of modular, ready-to-install, prefabricated vehicle roof is made separately from the vehicle body and is only joined to the vehicle body at the end of the assembly line in the automotive factory. Because of the considerable shortening of the assembly time at the end of the line in particular, vehicle roof modules of this type are gaining increasing importance.
In the case of such a known vehicle roof (DE 197 09 016 A1), the inner shell is divided into two layers in the area of the outside edges provided for support on the body frame, an upper layer of which can be placed on the body frame, whereas an under-layer can be curved down and is designed to clad the body frame. In this case, the areas of the inner shell that can be curved downwards are provided at suitable points with at least one pre-assembled element of the group consisting of sun visors, handles, ventilation grilles, interior lights, shock absorbing safety elements, airbags, etc. or with application points prepared for at least one of these elements.
Normally, motor vehicles are provided with lamps in the ceiling and/or the upper body frame, the side body pillars, and occasionally at other points too, like the interior mirror bracket, for the interior lighting of the passenger compartment.
Therefore, the known interior lamps for motor vehicles are only fitted at a few specific points. In the case of vehicles with limousine bodies, often only one lamp is provided, in the centre in the vicinity of the windscreen, and another lamp placed centrally above the rear seats. In spite of fitting lenses to the few interior lights, these are not able to illuminate the vehicle interior uniformly and clearly defined light islands are formed instead.
An object of the present invention is to provide a modular, prefabricated vehicle roof of the design described above with an integrated lighting system for the vehicle interior to illuminate the latter as uniformly and/or specifically as possible.
According to the present invention, there is provided a vehicle roof that is of a sandwich construction, having an inner shell molded from foam plastic which is designed as a roof interior, the roof being made separately from the vehicle body and having outside edges which can be placed on a vehicle frame and can be permanently connected to the latter; wherein a plurality of light conducting rods, preferably made from glass, are molded into the inner shell, the rods being connected to a light source and having light emitting ends which face, in use, a vehicle interior and are disposed at a distance from each other in the visible surface of the roof interior.
The lighting system proposed with the invention provides for foam molding several light conducting rods, preferably made from glass, into the inner shell which are connected to a light source and whose light emitting ends face the vehicle interior and are disposed at a distance from each other in the visible surface of the roof. As is known, light conducting glass rods can be of any shape and of any cross-section. They allow the transport of light energy without significant losses through inner total reflection, which can also be increased by silvering the boundary surfaces. Through a suitable choice of the refraction coefficients, the light energy transport can include all the directed beams arriving at the inlet surface and allow them to exit at the outlet surfaces, even if the shape of the glass rods differs considerably from the rectilinear form. It can be seen that the invention allows an adaptation of the lighting system to all the lighting requirements that can occur for vehicle interiors, the complete system already being an unobtrusive component of the vehicle roof module. The light emitting ends or outlet surfaces of the glass rods integrated into the visible surface of the roof are unobtrusive and therefore do not disturb the appearance. It is not necessary to install additional lamps.
A common light source can be provided for all the molded-in light conducting glass rods so that the lighting system has a very simple structure.
The light source can also be molded in to the inner shell so that the lighting system as a whole is not visible, with the exception of the light outlet surfaces of the glass rods on the roof interior.
To achieve a largely uniform lighting of the compartment, the light emitting ends of the glass rods, i.e. the light outlet surfaces of the glass rods, can be disposed in a regular distribution in the visible surface of the inner shell. In a preferred embodiment (shown in FIG. 5), the light emitting ends of the glass rods can be arranged in rows.
The lighting system opens up the advantageous possibility of adapting the essential section of the length of the light conducting glass rods to the curvature of the roof and molding them in at more or less equal and constant distances in relation to the visible surface of the inner shell. In this way, the lighting system more or less forms a further layer in the sandwich-type construction of the vehicle roof.
For practical purposes, the light conducting glass rods are connected to the light source in parallel with each other and extend in the parallel position as far as the relevant point of curvature. Through these measures, the lighting system has a clear and simple construction from the production point of view.